Hedegaard, M., Hakkarainen, P., & Engestrom, Y. (1984). Learning and teaching on a scientific basis: Methodological and Epistemological aspects of the activity theory of learning and teaching. Psykologisk Institut.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रHedegaard, Mariane, Pentti Hakkarainen, और Yrijo Engestrom. Learning and Teaching on a Scientific Basis: Methodological and Epistemological Aspects of the Activity Theory of Learning and Teaching. Dinamarca: Psykologisk Institut, 1984.
एमएलए (9वां संस्करण) प्रशस्ति पत्रHedegaard, Mariane, et al. Learning and Teaching on a Scientific Basis: Methodological and Epistemological Aspects of the Activity Theory of Learning and Teaching. Psykologisk Institut, 1984.
चेतावनी: ये उद्धरण हमेशा 100% सटीक नहीं हो सकते हैं.